biostudies-literatureUnknown7(3)<h4>Objectives:</h4> We examined the prevalence of and factors associated with usually purchasing tobacco online. <h4>Methods:</h4> We analyzed Waves 1 (2013-14) and 4 (2016-17) of the US Population Assessment of Tobacco and Health adult (18+) and youth (12-17) studies: 15,450 adults and 495 youth in 2013-14 and 15,037 adults and 465 youth in 2016-17. Z-tests compared the prevalence of usually purchasing tobacco online between waves and weighted multivariable regressions identified associations between purchasing online and sociodemographics. <h4>Results:</h4> The prevalence of usually purchasing tobacco online increased from 2.5% to 3.3% among adults (p < .05) and from 2.5% to 4.4% among youth (p < .05), generalizing to a US population of 2,000,000 adults and 35,000 youth. E-cigarettes anTobacco regulatory science155-169https://www.ebi.ac.uk/biostudies/studies/S-EPMC9518722biostudies-literatureWho Purchases Tobacco Online? Findings from Waves 1 and 4 of the Population Assessment of Tobacco and Health StudyPMC9518722falseWho Purchases Tobacco Online? Findings from Waves 1 and 4 of the Population Assessment of Tobacco and Health Study<h4>Objectives:</h4> We examined the prevalence of and factors associated with usually purchasing tobacco online. <h4>Methods:</h4> We analyzed Waves 1 (2013-14) and 4 (2016-17) of the US Population Assessment of Tobacco and Health adult (18+) and youth (12-17) studies: 15,450 adults and 495 youth in 2013-14 and 15,037 adults and 465 youth in 2016-17. Z-tests compared the prevalence of usually purchasing tobacco online between waves and weighted multivariable regressions identified associations between purchasing online and sociodemographics. <h4>Results:</h4> The prevalence of usually purchasing tobacco online increased from 2.5% to 3.3% among adults (p < .05) and from 2.5% to 4.4% among youth (p < .05), generalizing to a US population of 2,000,000 adults and 35,000 youth. E-cigarettes an2021-01-01T00:00:00Z2021 May2025-04-19T05:14:46.078Z2024-11-19T23:11:15.645ZS-EPMC9518722